With the help of massive amounts of computer muscle, they have scrubbed away cloud cover, filled in missing pixels, digitally stitched puzzle-piece pictures together, until the growing, thriving, sometimes dying planet is revealed in all its dynamic churn. The images are striking not just because of their vast sweep of geography and time but also because of their staggering detail.

The USGS' Landsat program will continue to take pictures, documenting how our land and water are changing. Through this program, this powerful history will be accessible to billions of people around the world.